Eyewear with chroma enhancement

ABSTRACT

Some embodiments provide a lens including a lens body and an optical filter configured to attenuate visible light in a plurality of spectral bands. Each of the plurality of spectral bands can include an absorptance peak with a spectral bandwidth, a maximum absorptance, and an integrated absorptance peak area within the spectral bandwidth. An attenuation factor obtained by dividing the integrated absorptance peak area within the spectral bandwidth by the spectral bandwidth of the absorptance peak can be greater than or equal to about 0.8 for the absorptance peak in each of the plurality of spectral bands.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/554,290, filed Aug. 28, 2019, titled EYEWEAR WITH CHROMA ENHANCEMENT,which is a continuation of U.S. application Ser. No. 15/199,174, filedJun. 30, 2016, titled EYEWEAR WITH CHROMA ENHANCEMENT, which is acontinuation of U.S. application Ser. No. 14/289,447, filed May 28,2014, titled EYEWEAR WITH CHROMA ENHANCEMENT, now U.S. Pat. No.9,383,594, which is a continuation of U.S. application Ser. No.13/029,997, filed Feb. 17, 2011, titled EYEWEAR WITH CHROMA ENHANCEMENT,now U.S. Pat. No. 8,770,749 which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/425,707, filed Dec.21, 2010, titled EYEWEAR AND LENSES WITH CHROMA ENHANCING FILTER, andU.S. Provisional Patent Application No. 61/324,706, filed Apr. 15, 2010,titled EYEWEAR AND LENSES WITH CHROMA ENHANCING FILTER. The entirecontents of each of these applications are incorporated by referenceherein and made a part of this specification.

BACKGROUND Field

This disclosure relates generally to eyewear and more particularly tolenses used in eyewear.

Description of Related Art

Eyewear can include optical elements that attenuate light in one or morewavelength bands. For example, sunglasses typically include a lens thatabsorbs a significant portion of light in the visible spectrum. Asunglass lens can have a dark film or coating that strongly absorbsvisible light, thereby significantly decreasing the luminoustransmittance of the lens. A lens can also be designed to have aspectral profile for another purpose, such as, for example, for indooruse, for use in sporting activities, for another particular use, or fora combination of uses.

SUMMARY

Example embodiments described herein have several features, no singleone of which is indispensible or solely responsible for their desirableattributes. Without limiting the scope of the claims, some of theadvantageous features will now be summarized.

Some embodiments provide a lens including a lens body and an opticalfilter within and/or outside of the lens body configured to attenuatevisible light in a plurality of spectral bands. In some embodiments inwhich the optical filter is within the lens body, the optical filter mayconstitute the lens body, or the optical filter and additionalcomponents may constitute the lens body. The optical filter can beconfigured to substantially increase the colorfulness, clarity, and/orvividness of a scene. The optical filter can be particularly suited foruse with eyewear and can allow the wearer of the eyewear to view a scenein high definition color (HD color). Each of the plurality of spectralbands can include an absorptance peak with a spectral bandwidth, amaximum absorptance, and an integrated absorptance peak area within thespectral bandwidth. The spectral bandwidth can be defined as the fullwidth of the absorptance peak at 80% of the maximum absorptance of theabsorptance peak. In some embodiments, an attenuation factor obtained bydividing the integrated absorptance peak area within the spectralbandwidth by the spectral bandwidth of the absorptance peak can begreater than or equal to about 0.8 for the absorptance peak in each ofthe plurality of spectral bands. In some embodiments, the spectralbandwidth of the absorptance peak in each of the plurality of spectralbands can be greater than or equal to about 20 nm.

In certain embodiments, the optical filter is at least partiallyincorporated into the lens body. The lens body can be impregnated with,loaded with, or otherwise comprise one or more organic dyes. Each of theone or more organic dyes can be configured to produce the absorptancepeak in one of the plurality of spectral bands. In some embodiments, theoptical filter is at least partially incorporated into a lens coatingdisposed over the lens body.

Some embodiments provide a method of manufacturing a lens. The methodcan include forming a lens having an optical filter configured toattenuate visible light in a plurality of spectral bands. Each of theplurality of spectral bands can include an absorptance peak with aspectral bandwidth, a maximum absorptance, and an integrated absorptancepeak area within the spectral bandwidth. The spectral bandwidth can bedefined as the full width of the absorptance peak at 80% of the maximumabsorptance of the absorptance peak. An attenuation factor of theabsorptance peak in each of the plurality of spectral bands can begreater than or equal to about 0.8 and less than 1. The attenuationfactor of an absorptance peak can be obtained by dividing the integratedabsorptance peak area within the spectral bandwidth by the spectralbandwidth of the absorptance peak.

In certain embodiments, a lens can be formed by forming a lens body andforming a lens coating over the lens body. At least a portion of theoptical filter can be incorporated into the lens body. At least aportion of the optical filter can be incorporated into the lens coating.The lens coating can include an interference coating.

In some embodiments, a lens body can be formed by a method includingforming a plurality of lens body elements and coupling the lens bodyelements to one another using one or more adhering layers. A polarizingfilm can be disposed between two of the plurality of lens body elements.In some embodiments, the polarizing film can be insert molded within thelens body.

Some embodiments provide a lens including a lens body and an opticalfilter characterized by a spectral absorptance profile including aplurality of absorptance peaks. Each of the plurality of absorptancepeaks can have a maximum absorptance, a spectral bandwidth defined asthe full width of the absorptance peak at 80% of the maximum absorptanceof the absorptance peak, and a center wavelength located at a midpointof the spectral bandwidth of the absorptance peak. The plurality ofabsorptance peaks can include a first absorptance peak having a centerwavelength between about 558 nm and about 580 nm and a secondabsorptance peak having a center wavelength between about 445 nm andabout 480 nm. The spectral bandwidth of each of the plurality ofabsorptance peaks can be between about 20 nm and about 50 nm.

In certain embodiments, each of the first absorptance peak and thesecond absorptance peak has an integrated absorptance peak area withinthe spectral bandwidth and an attenuation factor obtained by dividingthe integrated absorptance peak area by the spectral bandwidth of theabsorptance peak. The attenuation factor of each of the firstabsorptance peak and the second absorptance peak can be greater than orequal to about 0.8.

The plurality of absorptance peaks can include a third absorptance peakconfigured to substantially attenuate light at least between about 405nm and about 425 nm and a fourth absorptance peak configured tosubstantially attenuate light at least between about 650 nm and about670 nm, between about 705 nm and about 725 nm, or between about 700 nmand about 720 nm. In another embodiment, the third absorptance peak isconfigured to substantially attenuate light at least between about 400nm and about 420 nm. Each of the third absorptance peak and the fourthabsorptance peak can have an integrated absorptance peak area within thespectral bandwidth and an attenuation factor obtained by dividing theintegrated absorptance peak area by the spectral bandwidth of theabsorptance peak. The attenuation factor of each of the thirdabsorptance peak and the fourth absorptance peak can be greater than orequal to about 0.8.

Some embodiments provide a lens that includes a lens body with anoptical filter configured to increase the average chroma value of lighttransmitted through the lens within one or more portions of the visiblespectrum. The chroma value is the C* attribute of the CIE L*C*h* colorspace. At least one portion of the visible spectrum can include aspectral range of about 630 nm to about 660 nm. The increase in averagechroma value can include an increase that is perceivable by a human withsubstantially normal vision.

In certain embodiments, the optical filter is configured to increase theaverage chroma value of light transmitted through the lens within aspectral range of about 540 nm to about 600 nm by a relative magnitudeof greater than or equal to about 3% compared to the average chromavalue of light transmitted through a neutral filter within the samespectral range.

The optical filter can be configured to increase the average chromavalue of light transmitted through the lens within a spectral range ofabout 440 nm to about 480 nm by a relative magnitude of greater than orequal to about 15% compared to the average chroma value of lighttransmitted through a neutral filter within the same spectral range.

In some embodiments, the optical filter does not substantially decreasethe average chroma value of light transmitted through the lens withinthe one or more portions of the visible spectrum when compared to theaverage chroma value of light transmitted through a neutral filter. Incertain embodiments, the optical filter does not substantially decreasethe average chroma value of light transmitted through the lens within aspectral range of about 440 nm to about 660 nm when compared to theaverage chroma value of light transmitted through a neutral filter.

The optical filter can be configured to increase the average chromavalue of light transmitted through the lens within a spectral range ofabout 630 to about 660 nm by a relative magnitude of greater than orequal to about 3% compared to the average chroma value of lighttransmitted through a neutral filter within the same spectral range.

The optical filter can be at least partially incorporated into the lensbody. For example, the lens body can be loaded with a plurality oforganic dyes, each of the plurality of organic dyes configured toincrease the average chroma value of light transmitted through the lenswithin one or more portions of the visible spectrum.

In some embodiments, the optical filter is at least partiallyincorporated into a lens coating disposed over at least a portion of thelens body. For example, the optical filter can include an interferencecoating.

In some embodiments, the optical filter can be at least partiallyincorporated into an adhering layer, a polarizing layer, or acombination of the adhering layer and the polarizing layer.

Certain embodiments provide a method of manufacturing a lens, the methodincluding forming a lens including an optical filter configured toincrease the average chroma value of light transmitted through the lenswithin one or more portions of the visible spectrum. At least oneportion of the visible spectrum can include a spectral range of about630 nm to about 660 nm. The increase in average chroma value can includean increase that is perceivable by a human with substantially normalvision.

The step of forming a lens can include forming a lens body and forming alens coating over the lens body. At least a portion of the opticalfilter can be incorporated into the lens body. At least a portion of theoptical filter can be incorporated into the lens coating. For example,the lens coating can include an interference coating.

The step of forming a lens body can include forming a plurality of lensbody elements and coupling the lens body elements to one another usingone or more adhering layers. A polarizing film can be disposed betweentwo of the plurality of lens body elements. The lens can include one ormore components that substantially absorb ultraviolet radiation,including near ultraviolet radiation. In some embodiments, thepolarizing film can be insert molded into the lens body.

Some embodiments provide a lens including a lens body and an opticalfilter configured to increase the average chroma value of lighttransmitted through the lens within one or more portions of the visiblespectrum. One of the one or more portions of the visible spectrum caninclude a spectral range of about 540 nm to about 600 nm. The increasein average chroma value can include an increase that is perceivable by ahuman with substantially normal vision.

Certain embodiments provide a lens including a lens body and an opticalfilter configured to increase the average chroma value of lighttransmitted through the lens within one or more portions of the visiblespectrum. Three of the one or more portions of the visible spectrum caninclude a spectral range of about 440 nm to about 510 nm, a spectralrange of about 540 nm to about 600 nm, and a spectral range of about 630nm to about 660 nm. The increase in average chroma value can include anincrease that is perceivable by a human with substantially normalvision.

Some embodiments provide a lens for eyewear including a lens body and anoptical filter including a plurality of organic dyes. Each of theplurality of organic dyes is configured to attenuate visible light inone or more spectral bands. Each of the one or more spectral bandsincludes an absorptance peak with a spectral bandwidth, a maximumabsorptance, and an integrated absorptance peak area within the spectralbandwidth. The spectral bandwidth can be defined as the full width ofthe absorptance peak at 80% of the maximum absorptance of theabsorptance peak. The attenuation factor of an absorptance peak can beobtained by dividing the integrated absorptance peak area within thespectral bandwidth by the spectral bandwidth of the absorptance peak.For one or more of the plurality of organic dyes, the attenuation factorof at least one absorptance peak is greater than or equal to about 0.8.

For example, one or more of the plurality of organic dyes can include anabsorptance profile having a blue light absorptance peak with a centerwavelength between about 470 nm and about 480 nm. In some embodiments,the spectral bandwidth of the blue light absorptance peak can be greaterthan or equal to about 20 nm, and the attenuation factor of the bluelight absorptance peak can be greater than or equal to about 0.9.

One or more of the plurality of organic dyes can include an absorptanceprofile having a yellow light absorptance peak with a center wavelengthbetween about 560 nm and about 580 nm. In some embodiments, the spectralbandwidth of the yellow light absorptance peak can be greater than orequal to about 20 nm, and the attenuation factor of the yellow lightabsorptance peak can be greater than or equal to about 0.85.

One or more of the plurality of organic dyes can include an absorptanceprofile having a red light absorptance peak with a center wavelengthbetween about 600 nm and about 680 nm. In some embodiments, the spectralbandwidth of the red light absorptance peak can be greater than or equalto about 20 nm, and the attenuation factor of the red light absorptancepeak is greater than or equal to about 0.9.

Each of the plurality of organic dyes can be selected to increase thechroma value of light transmitted through the lens in one or more chromaenhancement windows. The one or more chroma enhancement windows caninclude a first spectral range of about 440 nm to about 510 nm, a secondspectral range of about 540 nm to about 600 nm, a third spectral rangeof about 630 nm to about 660 nm, or any combination of the first,second, and third spectral ranges.

Certain embodiments provide a lens including a lens body and an opticalfilter configured to attenuate visible light in a plurality of spectralbands. Each of the plurality of spectral bands includes an absorptancepeak with a spectral bandwidth, a maximum absorptance, lower and upperedge portions that are substantially below the maximum absorptance, anda middle portion positioned between the lower and upper edge portionsand including the maximum absorptance and a region substantially nearthe maximum absorptance. In some embodiments, one of the lower or upperedge portions of at least one absorptance peak lies within an objectspectral window including a spectral region in which the object emits orreflects a substantial visible stimulus.

The optical filter can be configured such that one of the lower or upperedge portions of at least one absorptance peak lies within a backgroundspectral window. The background spectral window includes a spectralregion in which the background emits or reflects a substantial visiblestimulus.

The optical filter can be at least partially incorporated into the lensbody. The lens body can be impregnated with a plurality of organic dyes,each of the plurality of organic dyes configured to produce theabsorptance peak in one of the plurality of spectral bands.

The optical filter can be at least partially incorporated into a lenscoating disposed over at least a portion of the lens body. For example,the optical filter can include an interference coating. The opticalfilter can also be at least partially incorporated into an adheringlayer, a polarizing layer, or a combination of the adhering layer andthe polarizing layer.

Some embodiments provide a method of manufacturing a lens, the methodincluding forming an optical filter configured to attenuate visiblelight in a plurality of spectral bands. Each of the plurality ofspectral bands including an absorptance peak with a spectral bandwidth,a maximum absorptance, lower and upper edge portions that aresubstantially below the maximum absorptance, and a middle portionpositioned between the lower and upper edge portions and including themaximum absorptance and a region substantially near the maximumabsorptance. One of the lower or upper edge portions of at least oneabsorptance peak can lie within an object spectral window including aspectral region in which the object emits or reflects a substantialvisible stimulus.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should in no way be interpreted as limitingthe scope of the inventions. In addition, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure. Any feature or structure can beremoved or omitted. Throughout the drawings, reference numbers may bereused to indicate correspondence between reference elements.

FIG. 1A is a perspective view of a pair of spectacles incorporatinglenses with a chroma-enhancing optical filter.

FIG. 1B is a cross-sectional view of one of the lenses shown in FIG. 1A.

FIG. 2A is a graph showing sensitivity curves for cone photoreceptorcells in the human eye.

FIG. 2B is a graph showing the 1931 CIE XYZ tristimulus functions.

FIG. 3 is a graph showing the spectral absorptance profile of a sunglasslens with an optical filter.

FIG. 4A is a graph showing the percentage difference in chroma of a lenswith the absorptance profile shown in FIG. 3 compared to a neutralfilter.

FIG. 4B is a chromaticity diagram for the lens having the absorptanceprofile shown in FIG. 3 .

FIG. 5 is a graph showing the spectral absorptance profile of an opticalfilter.

FIG. 6A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 5 and of neutral filter.

FIG. 6B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 5 compared to aneutral filter.

FIG. 7 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 5 .

FIG. 8 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 9A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 8 and of a neutral filter.

FIG. 9B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 8 compared to aneutral filter.

FIG. 10 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 8 .

FIG. 11 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 12A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 11 and of a neutral filter.

FIG. 12B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 11 compared to aneutral filter.

FIG. 13 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 11 .

FIG. 14 is a graph showing the spectral absorptance profiles of threedifferent optical filters.

FIG. 15A is a graph showing the chroma profiles of three filters, eachfilter with one of the absorptance profiles shown in FIG. 14 , and of aneutral filter.

FIG. 15B is a graph showing the percentage differences in chroma of thethree different filters with the absorptance profiles shown in FIG. 14compared to a neutral filter.

FIG. 16 is a graph showing the spectral absorptance profiles of threedifferent optical filters.

FIG. 17A is a graph showing the chroma profiles of three filters, eachfilter with one of the absorptance profiles shown in FIG. 16 , and of aneutral filter.

FIG. 17B graph showing the percentage differences in chroma of the threedifferent filters with the absorptance profiles shown in FIG. 16compared to a neutral filter.

FIG. 18 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 19A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 18 and of a neutral filter.

FIG. 19B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 18 compared to aneutral filter.

FIG. 20 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 18 .

FIG. 21 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 22A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 21 and of a neutral filter.

FIG. 22B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 21 compared to aneutral filter.

FIG. 23 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 21 .

FIG. 24 is a graph showing the luminous efficiency profile of the humaneye.

FIG. 25 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 26A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 25 and of a neutral filter.

FIG. 26B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 25 compared to aneutral filter.

FIG. 27 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 25 .

FIG. 28 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 29A is a graph showing the chroma profile of a filter with theabsorptance profile shown in FIG. 28 and of a neutral filter.

FIG. 29B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 28 compared to aneutral filter.

FIG. 30 is a chromaticity diagram for an optical filter having theabsorptance profile shown in FIG. 28 .

FIG. 31 is a graph showing the spectral absorptance profile of anon-polarized lens with an example optical filter.

FIG. 32A is a graph showing the chroma profile of a non-polarized lenswith the spectral absorptance profile shown in FIG. 31 and of a neutralfilter.

FIG. 32B is a graph showing the percentage difference in chroma of alens with the absorptance profile shown in FIG. 31 compared to a neutralfilter.

FIG. 33 is a chromaticity diagram for the lens with the spectralabsorptance profile shown in FIG. 31 .

FIG. 34 is a graph showing the spectral absorptance profile of anon-polarized lens with another example optical filter.

FIG. 35A is a graph showing the chroma profile of the lens with thespectral absorptance profile shown in FIG. 34 and of a neutral filter.

FIG. 35B is a graph showing the percentage difference in chroma of alens with the absorptance profile shown in FIG. 34 compared to a neutralfilter.

FIG. 36 is a chromaticity diagram for the lens with the spectralabsorptance profile shown in FIG. 34 .

FIG. 37 is a graph showing the spectral absorptance profile of anotheroptical filter.

FIG. 38A is a graph showing the chroma profile of a filter withabsorptance profile shown in FIG. 37 and of a neutral filter.

FIG. 38B is a graph showing the percentage difference in chroma of afilter with the absorptance profile shown in FIG. 37 compared to aneutral filter.

FIG. 39 is a chromaticity diagram for the filter with the spectralabsorptance profile shown in FIG. 37 .

FIG. 40 is a graph showing the spectral absorptance profile of a castlens with an optical filter.

FIG. 41A is a graph showing the chroma profile of a lens with theabsorptance profile shown in FIG. 40 and of a neutral filter.

FIG. 41B is a graph showing the percentage difference in chroma of alens with the absorptance profile shown in FIG. 40 compared to a neutralfilter.

FIG. 42 is a chromaticity diagram for the lens with the spectralabsorptance profile shown in FIG. 40 .

FIGS. 43-48 illustrate example chroma enhancement window configurationsfor optical filters.

FIG. 49 illustrates a spectral power distribution representative of thelight reflected or emitted from a golf ball under outdoor illuminationconditions.

FIG. 50 is a graph showing the absorptance profile of a cast lens havingan optical filter with the absorptance profile of FIG. 40 and apolarizer having a substantially neutral gray tint.

FIG. 51 is a graph showing the percentage difference in chroma of a lenswith the absorptance profile shown in FIG. 50 compared to a neutralfilter.

FIG. 52 is a chromaticity diagram for the lens with the optical filtershown in FIG. 50 .

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Although certain preferred embodiments and examples are disclosed below,inventive subject matter extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses, and tomodifications and equivalents thereof. Thus, the scope of the claimsappended hereto is not limited by any of the particular embodimentsdescribed below. For example, in any method or process disclosed herein,the acts or operations of the method or process may be performed in anysuitable sequence and are not necessarily limited to any particulardisclosed sequence. Various operations may be described as multiplediscrete operations in turn, in a manner that may be helpful inunderstanding certain embodiments; however, the order of descriptionshould not be construed to imply that these operations are orderdependent. Additionally, the structures described herein may be embodiedas integrated components or as separate components. For purposes ofcomparing various embodiments, certain aspects and advantages of theseembodiments are described. Not necessarily all such aspects oradvantages are achieved by any particular embodiment. Thus, for example,various embodiments may be carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other aspects or advantages as may also be taughtor suggested herein.

Objects that humans can visually observe in the environment typicallyemit, reflect, or transmit visible light from one or more surfaces. Thesurfaces can be considered an array of points that the human eye isunable to resolve any more finely. Each point on the surfaces does notemit, reflect, or transmit a single wavelength of light; rather, itemits, reflects, or transmits a broad spectrum of wavelengths that areinterpreted as a single color in human vision. Generally speaking, ifone were to observe the corresponding “single wavelength” of light forthat interpreted color (for example, a visual stimulus having a verynarrow spectral bandwidth, such as 1 nm), it would appear extremelyvivid when compared to a color interpreted from a broad spectrum ofobserved wavelengths.

It has been discovered that an optical filter can be configured toremove the outer portions of a broad visual stimulus to make colorsappear more vivid as perceived in human vision. The outer portions of abroad visual stimulus refer to wavelengths that, when substantially,nearly completely, or completely attenuated, decrease the bandwidth ofthe stimulus such that the vividness of the perceived color isincreased. An optical filter for eyewear can be configured tosubstantially increase the colorfulness, clarity, and/or vividness of ascene. Such an optical filter for eyewear can allow the wearer to viewthe scene in high definition color (HD color). In some embodiments,portions of a visual stimulus that are not substantially attenuatedinclude at least the wavelengths for which cone photoreceptor cells inthe human eye have the greatest sensitivity. In certain embodiments, thebandwidth of the color stimulus when the optical filter is appliedincludes at least the wavelengths for which the cone photoreceptor cellshave the greatest sensitivity. In some embodiments, a person wearing alens incorporating an optical filter disclosed herein may perceive asubstantial increase in the clarity of a scene. The increase inperceived clarity may result, for example, from increased contrast,increased chroma, or a combination of factors.

The vividness of interpreted colors is correlated with an attributeknown as the chroma value of a color. The chroma value is one of theattributes or coordinates of the CIE L*C*h* color space. Together withattributes known as hue and lightness, the chroma can be used to definecolors that are perceivable in human vision. It has been determined thatvisual acuity is positively correlated with the chroma values of colorsin an image. In other words, the visual acuity of an observer is greaterwhen viewing a scene with high chroma value colors than when viewing thesame scene with lower chroma value colors.

An optical filter can be configured to enhance the chroma profile of ascene when the scene is viewed through a lens that incorporates theoptical filter. The optical filter can be configured to increase ordecrease chroma in one or more chroma enhancement windows in order toachieve any desired effect. The chroma-enhancing optical filter can beconfigured to preferentially transmit or attenuate light in any desiredchroma enhancement windows. Any suitable process can be used todetermine the desired chroma enhancement windows. For example, thecolors predominantly reflected or emitted in a selected environment canbe measured, and a filter can be adapted to provide chroma enhancementin one or more spectral regions corresponding to the colors that arepredominantly reflected or emitted.

In the embodiment illustrated in FIG. 1A, eyewear 100 includes lenses102 a, 102 b having a chroma-enhancing optical filter. Thechroma-enhancing filter generally changes the colorfulness of a sceneviewed through one or more lenses 102 a, 102 b, compared to a sceneviewed through a lens with the same luminous transmittance but adifferent spectral transmittance profile. The eyewear can be of anytype, including general-purpose eyewear, special-purpose eyewear,sunglasses, driving glasses, sporting glasses, indoor eyewear, outdooreyewear, vision-correcting eyewear, contrast-enhancing eyewear, eyeweardesigned for another purpose, or eyewear designed for a combination ofpurposes.

In the embodiment illustrated in FIG. 1B, a lens 102 incorporatesseveral lens elements. The lens elements include a lens coating 202, afirst lens body element 204, a film layer 206, and a second lens bodyelement 208. Many variations in the configuration of the lens 102 arepossible. For example, the lens 102 can include a polarizing layer, oneor more adhesive layers, a photochromic layer, an antireflectioncoating, a mirror coating, an interference coating, a scratch resistantcoating, a hydrophobic coating, an anti-static coating, other lenselements, or a combination of lens components. If the lens 102 includesa photochromic layer, the photochromic material can include a neutraldensity photochromic or any other suitable photochromic. At least someof the lens components and/or materials can be selected such that theyhave a substantially neutral visible light spectral profile.Alternatively, the visible light spectral profiles can cooperate toachieve any desired lens chromaticity, a chroma-enhancing effect,another goal, or any combination of goals. The polarizing layer, thephotochromic layer, and/or other functional layers can be incorporatedinto the film layer 206, the lens coating 202, one or more of the lensbody elements 204, 208, or can be incorporated into additional lenselements. In some embodiments, a lens 102 incorporates fewer than allthe lens elements shown in FIG. 1B.

The lens can include a UV absorption layer or a layer that includes UVabsorption outside of the optical filter layer. Such a layer candecrease bleaching of the optical filter.

In addition, UV absorbing agents can be disposed in any lens componentor combination of lens components.

The lens body elements 204, 208 can be made from glass, a polymericmaterial, a co-polymer, a doped material, another material, or acombination of materials. In some embodiments, one or more portions ofthe optical filter can be incorporated into the lens coating 202, intoone or more lens body elements 204, 208, into a film layer 206, into anadhesive layer, into a polarizing layer, into another lens element, orinto a combination of elements.

The lens body elements 204, 208 can be manufactured by any suitabletechnique, such as, for example, casting or injection molding. Injectionmolding can expose a lens to temperatures that degrade or decomposecertain dyes. Thus, when the optical filter is included in one or morelens body elements, a wider range of dyes may be selected for inclusionin the optical filter when the lens body elements are made by castingthan when the lens body is made by injection molding. Further, a widerrange of dyes or other optical filter structures may be available whenthe optical filter is implemented at least partially in a lens coating.

A sunglass lens substantially attenuates light in the visible spectralregion.

However, the light need not be attenuated uniformly or even generallyevenly across the visible spectrum. Instead, the light that isattenuated can be tailored to achieve a specific chroma-enhancingprofile or another goal. A sunglass lens can be configured to attenuatelight in spectral bands that are selected such that the scene receivesone or more of the improvements or characteristics disclosed herein.Such improvements or characteristics can be selected to benefit thewearer during one or more particular activities or in one or morespecific environments.

To design a filter that increases chroma for an array of colors, one canaccount for the mechanisms involved in the eye's perception of color.The photopically adapted eye (e.g., the human eye) shows peaksensitivities at 440, 545, and 565 nm. These peak sensitivitiescorrespond to each of three optical sensors found in the eye's retinaknown as cones. The location and shape of the cone sensitivity profileshave recently been measured with substantial accuracy in Stockman andSharpe, “The spectral sensitivities of the middle- andlong-wavelength-sensitive cones derived from measurements in observersof known genotype,” Vision Research 40 (2000), pp. 1711-1737, which isincorporated by reference herein and made a part of this specification.The sensitivity profiles S, M, L for cone photoreceptor cells in thehuman eye as measured by Stockman and Sharpe are shown in FIG. 2A.

The cone sensitivity profiles can be converted from sensitivity data toquantities describing color such as, for example, the CIE tristimuluscolor values. The 1931 CIE XYZ tristimulus functions are shown in FIG.2B. In some embodiments, the CIE tristimulus color values are used todesign an optical filter. For example, the CIE color values can be usedto calculate the effect of an optical filter on perceived color usingvalues of chroma, C*, in the CIE L*C*h* color space.

The human cone sensitivities can be converted to the 1931 CIE XYZ colorspace using the linear transformation matrix M described in Golz andMacleod, “Colorimetry for CRT displays,” J. Opt. Soc. Am. A vol. 20, no.5 (May 2003), pp. 769-781, which is incorporated by reference herein andmade a part of this specification. The linear transformation is shown inEq. 1:

$\begin{matrix}{M = \begin{bmatrix}0.17156 & 0.52901 & 0.02199 \\{{0.1}5955} & {{0.4}8553} & {{0.0}4298} \\0.01916 & {{0.0}3989} & 1.03993\end{bmatrix}} & \left( {{Eq}.1} \right)\end{matrix}$ $\begin{bmatrix}L \\M \\S\end{bmatrix} = {M\begin{bmatrix}X \\Y \\Z\end{bmatrix}}$

To solve for the 1931 CIE XYZ color space values (X Y Z), the Stockmanand Sharpe 2000 data can be scaled by factors of 0.628, 0.42, and 1.868for L, M, and S cone sensitivities, respectively, and multiplied by theinverse of the linear transformation matrix M in the manner shown inEqs. 2-1 and 2-2:

$\begin{matrix}{\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {M^{- 1}\begin{bmatrix}L \\M \\S\end{bmatrix}}} & \left( {{{Eq}.2} - 1} \right)\end{matrix}$

where

(Eq. 2-2)

$\begin{matrix}{M^{- 1} = \begin{bmatrix}{{2.8}9186} & {{- {3.1}}3517} & {{0.1}9072} \\{{0.9}5178} & {{1.0}2077} & {{- {0.0}}2206} \\{{- {0.0}}1677} & {{0.0}9691} & {{0.9}5724}\end{bmatrix}} & \left( {{{Eq}.2} - 2} \right)\end{matrix}$

The CIE tristimulus values, X Y Z, can be converted to the 1976 CIEL*a*b* color space coordinates using the nonlinear equations shown inEqs. 3-1 through 3-7.

Where X_(n)=95.02, Y_(n)=100.00, and Z_(n)=108.82,

$\begin{matrix}{L^{*} = {{116\sqrt[3]{Y/Y_{n}}} - 16}} & \left( {{{Eq}.3} - 1} \right)\end{matrix}$ $\begin{matrix}{a^{*} = {500\left( {\sqrt[3]{X/X_{n}} - \sqrt[3]{Y/Y_{n}}} \right)}} & \left( {{{Eq}.3} - 2} \right)\end{matrix}$ $\begin{matrix}{b^{*} = {200\left( {\sqrt[3]{Y/Y_{n}} - \sqrt[3]{Z/Z_{n}}} \right)}} & \left( {{{Eq}.3} - 3} \right)\end{matrix}$ IfX/X_(n), Y/Y_(n), orZ/Z_(n) < 0.008856, then:$\begin{matrix}{L^{*} = {903.3\left( {Y/Y_{n}} \right)}} & \left( {{{Eq}.3} - 4} \right)\end{matrix}$ $\begin{matrix}{a^{*} = {50{0\left\lbrack {{f\left( {X/X_{n}} \right)} - {f\left( {Y/Y_{n}} \right)}} \right\rbrack}}} & \left( {{{Eq}.3} - 5} \right)\end{matrix}$ $\begin{matrix}{b^{*} = {20{0\left\lbrack {{f\left( {Y/Y_{n}} \right)} - {f\left( {Z/Z_{n}} \right)}} \right\rbrack}}} & \left( {{{Eq}.3} - 6} \right)\end{matrix}$ Forα > 0.008856; α = X/X_(n), Y/Y_(n), orZ/Z_(n)${f(\alpha)} = \sqrt[3]{\alpha}$ Otherwise: $\begin{matrix}{{f(\alpha)} = {{{7.8}7\alpha} + {16/116}}} & \left( {{{Eq}.3} - 7} \right)\end{matrix}$

Chroma or C* can be then be calculated by further conversion from CIEL*a*b* to CIE L*C*h* using Eq. 4:

C*=√{square root over (a* ² +b* ²)}  (Eq. 4)

As mentioned above, the colors observed in the physical world arestimulated by wide bands of wavelengths. To simulate this and thencalculate the effects of an optical filter, filtered and non-filteredbands of light are used as input to the cone sensitivity space. Theeffect on chroma can then be predicted via the transformations listedabove.

When inputting a spectrum of light to the cone sensitivity space, themechanism of color recognition in the human eye can be accounted for.Color response by the eye is accomplished by comparing the relativesignals of each of the three cones types: S, M, and L. To model thiswith broad band light, a sum of the intensities at each wavelength inthe input spectrum is weighted according to the cone sensitivity at thatwavelength. This is repeated for all three cone sensitivity profiles. Anexample of this calculation is shown in Table A:

TABLE A Input light Total weighted Wavelength intensity, L Cone LWeighted light intensity, λ (nm) arbitrary units Sensitivity lightintensity normalized 500 0.12 × 0.27 = 0.032 501 0.14 × 0.28 = 0.039 5020.16 × 0.31 = 0.05 503 0.17 × 0.33 = 0.056 504 0.25 × 0.36 = 0.09 5050.41 × 0.37 = 0.152 506 0.55 × 0.39 = 0.215 507 0.64 × 0.41 = 0.262 5080.75 × 0.42 = 0.315 509 0.63 × 0.44 = 0.277 510 0.54 × 0.46 = 0.248 5110.43 × 0.48 = 0.206 512 0.25 × 0.49 = 0.123 513 0.21 × 0.50 = 0.105 5140.18 × 0.51 = 0.092 515 0.16 × 0.52 = 0.083 516 0.15 × 0.54 = 0.081 5170.13 × 0.56 = 0.073 518 0.11 × 0.57 = 0.063 519 0.09 × 0.59 = 0.053 5200.08 × 0.61 = 0.049 Sum 6.15 2.664 0.433

Normalized weighted light intensities for all three cone types can thenbe converted to the 1931 CIE XYZ color space via a linear transformationmatrix, M. This conversion facilitates further conversion to the 1976CIE L*a*b* color space and the subsequent conversion to the CIE L*C*hcolor space to yield chroma values.

To simulate the effect of a filter placed between the eye and thephysical world, an input band of light can be modified according to aprospective filter's absorption characteristics. The weighted lightintensity is then normalized according to the total sum of light that istransmitted through the filter.

In certain embodiments, to test the effect of a filter on various colorsof light, the spectral profile or at least the bandwidth of an input isdetermined first. The appropriate bandwidth for the model's input istypically affected by the environment of use for the optical filter. Areasonable bandwidth for a sunglass lens can be about 30 nm, since thisbandwidth represents the approximate bandwidth of many colors perceivedin the natural environment. Additionally, 30 nm is a narrow enoughbandwidth to permit transmitted light to fall within responsive portionsof the cone sensitivity functions, which are approximately twice thisbandwidth. A filter designed using a 30 nm input bandwidth will alsoimprove the chroma of colors having other bandwidths, such as 20 nm or80 nm. Thus, the effect of a filter on chroma can be determined usingcolor inputs having a 30 nm bandwidth or another suitable bandwidth thatis sensitive to a wide range of natural color bandwidths.

Other bandwidths are possible. The bandwidth can be significantlywidened or narrowed from 30 nm while preserving the chroma-enhancingproperties of many filter designs. The 30 nm bandwidth described aboveis representative of wider or narrower input bandwidths that can be usedto produce desired features of an optical filter. The term “bandwidth”is used herein in its broad and ordinary sense. In some embodiments, thebandwidth of a peak encompasses the full width of a peak at half of thepeak's maximum value (FWHM value) and any other commonly usedmeasurements of bandwidth.

A sample calculation of the normalized L weighted light intensity usingthe 30 nm bandwidth and an example filter is shown in Table B:

TABLE B Total weighted Incoming light Filtered L L Weighted Wavelengthintensity L Cone weighted Light Intensity, λ (nm) arbitrary units FilterT % Sensitivity light intensity Normalized 499 0 × 0.12 × 0.25 = 0.00500 1 × 0.34 × 0.27 = 0.09 501 1 × 0.41 × 0.28 = 0.11 502 1 × 0.42 ×0.31 = 0.13 503 1 × 0.44 × 0.33 = 0.15 504 1 × 0.51 × 0.36 = 0.18 505 1× 0.55 × 0.37 = 0.20 506 1 × 0.61 × 0.39 = 0.24 507 1 × 0.78 × 0.41 =0.32 508 1 × 0.75 × 0.42 = 0.32 509 1 × 0.85 × 0.44 = 0.37 510 1 × 0.87× 0.46 = 0.40 511 1 × 0.91 × 0.48 = 0.44 512 1 × 0.95 × 0.49 = 0.47 5131 × 0.96 × 0.50 = 0.48 514 1 × 0.97 × 0.51 = 0.49 515 1 × 0.96 × 0.52 =0.50 516 1 × 0.98 × 0.54 = 0.53 517 1 × 0.76 × 0.56 = 0.43 518 1 × 0.75× 0.57 = 0.43 519 1 × 0.61 × 0.59 = 0.36 520 1 × 0.55 × 0.61 = 0.34 5211 × 0.48 × 0.72 = 0.35 522 1 × 0.42 × 0.78 = 0.33 523 1 × 0.41 × 0.81 =0.33 524 1 × 0.35 × 0.84 = 0.29 525 1 × 0.33 × 0.85 = 0.28 526 1 × 0.31× 0.88 = 0.27 527 1 × 0.28 × 0.87 = 0.24 528 1 × 0.27 × 0.89 = 0.24 5291 × 0.22 × 0.91 = 0.20 530 0 × 0.18 × 0.92 = 0.00 531 0 × 0.15 × 0.93 =0.00 Sum 30 18.4 9.51 0.52

In some embodiments, an optical filter is designed by using spectralprofiles of candidate filters to calculate the effect of the candidatefilters on chroma. In this way, changes in the filter can be iterativelychecked for their effectiveness in achieving a desired result.Alternatively, filters can be designed directly via numericalsimulation. Examples and comparative examples of optical filters and theeffects of those optical filters on chroma are described herein. In eachcase, the chroma of input light passing through each filter is comparedto the chroma of the same input without filtering. Plots of“absorptance%” against visible spectrum wavelengths show the spectralabsorptance profile of the example or comparative example opticalfilter. Each plot of “chroma, C*, relative” against visible spectrumwavelengths shows the relative chroma of a 30 nm wide light stimulus ofuniform intensity after the stimulus passes through awavelength-dependent optical filter as a thinner curve on the plot, withthe center wavelength of each stimulus being represented by the valueson the horizontal axis. Each plot of “chroma, C*, relative” also showsthe relative chroma of the same 30 nm wide light stimulus passingthrough a neutral filter that attenuates the same average percentage oflight within the bandwidth of the stimulus as the wavelength-dependentoptical filter.

One goal of filter design may be to determine the overall colorappearance of a lens. In some embodiments, the perceived color ofoverall light transmitted from the lens is bronze, amber, violet, gray,or another color. In some cases, the consumer has preferences that aredifficult to account for quantitatively. In certain cases, lens coloradjustments can be accomplished within the model described in thisdisclosure. The impact of overall color adjustments to the filter designcan be calculated using a suitable model. In some cases, coloradjustments can be made with some, little, or no sacrifice to the chromacharacteristics being sought. In some embodiments, a lens has an overallcolor with a relatively low chroma value. For example, the lens can havea chroma value of less than 60. A chroma-increasing optical filter usedin such a lens may provide increased colorfulness for at least somecolors as compared to when the same optical filter is used in a lenswith an overall color having a higher chroma value.

A comparative example of an optical filter has properties as shown inFIGS. 3, 4A, and 4B. FIG. 3 shows the absorptance profile of acomparative example lens with an optical filter, the LAGOON 189-02 greylens available from Maui Jim, Inc. of Peoria, Illinois. FIG. 4A shows apercentage difference in chroma between the output of a lens having theabsorptance profile shown in FIG. 3 and the output of a filter thatuniformly attenuates the same average percentage of light within eachstimulus band as the lens of FIG. 3 , wherein the input is a 30 nmuniform intensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band. As can be seen in FIG. 4A, thecomparative example lens characterized by the absorptance profile shownin FIG. 3 provides some increase in chroma in certain spectral regionsand some decrease in chroma in other spectral regions, compared to afilter that provides neutral attenuation for each 30 nm stimulus. Theaverage percentage attenuation provided by the neutral attenuationfilter for each stimulus is the same as the average percentageattenuation provided by the comparative example filter. Specificbandwidths of light with uniform intensity were used to calculate therelative chroma profiles in this disclosure. In figures where therelative chroma profile of a filter is shown, the scale is maintainedconstant throughout this disclosure such that relative chroma shown inone figure can be compared to relative chroma shown in other figures,unless otherwise noted. In some figures, the chroma profile of a filtermay be clipped in order to show detail and maintain consistent scale.

In some embodiments, an optical filter is configured to increase ormaximize chroma in the blue to blue-green region of the visiblespectrum. A filter with such a configuration can have an absorptancepeak centered at about 478 nm or at about 480 nm, as shown in FIG. 5 .The full width at half maximum (FWHM) of the absorptance peak shown inFIG. 5 is about 20 nm. However, other absorptance peak widths can beused, including bandwidths greater than or equal to about 10 nm, greaterthan or equal to about 15 nm, greater than or equal to about 20 nm, lessthan or equal to about 60 nm, less than or equal to about 50 nm, lessthan or equal to about 40 nm, between about 10 nm and about 60 nm, orbetween any of the other foregoing values. The bandwidth of anabsorptance peak can be measured in any suitable fashion in addition toor in place of FWHM. For example, the bandwidth of an absorptance peakcan include the full width of a peak at 80% of the maximum. FIG. 6Ashows the relative chroma, as a function of wavelength, of a filterhaving the absorptance profile shown in FIG. 5 . Once again, the thickerblack line corresponds to the chroma profile of a neutral filter havingthe same integrated light transmittance within each 30 nm stimulus bandas within each corresponding band of the optical filter shown in FIG. 5. FIG. 6B shows a percentage difference in chroma between the output ofthe optical filter of FIG. 5 and the output of a filter that uniformlyattenuates the same average percentage of light within each stimulusband as the optical filter of FIG. 5 , wherein the input is a 30 nmuniform intensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band.

A CIE xy chromaticity diagram for the optical filter having anabsorptance profile as shown in FIG. 5 is provided in FIG. 7 . Thechromaticity diagram shows the chromaticity of the filter as well as thegamut of an RGB color space. Each of the chromaticity diagrams providedin this disclosure shows the chromaticity of the associated filter orlens, where the chromaticity is calculated using CIE illuminant D65.

In certain embodiments, an optical filter is configured to increase ormaximize chroma in the blue region of the visible spectrum. A filterwith such a configuration can provide an absorptance peak with a centerwavelength at about 453 nm, at about 450 nm, or between about 445 nm andabout 460 nm. The bandwidth of the absorptance peak can be greater thanor equal to about 10 nm, greater than or equal to about 15 nm, greaterthan or equal to about 20 nm, or another suitable value.

In some embodiments, an optical filter is configured to increase ormaximize chroma across several, many, or most colors, or at least manycolors that are commonly encountered in the environment of the wearer.Such an optical filter can include a plurality of absorptance peaks. Forexample, FIG. 8 shows a spectral absorptance profile of an embodiment ofan optical filter including four absorptance peaks with centerwavelengths at about 415 nm, about 478 nm, about 574 nm, and about 715nm. Relative chroma profiles and a chromaticity diagram for the examplefilter are shown in FIGS. 9A, 9B and 10 . The relative chroma profileshown in FIG. 9A shows that the optical filter of

FIG. 8 provides a substantial increase in chroma in at least fourspectral windows compared to a neutral filter having the same integratedlight transmittance within each 30 nm stimulus band as within eachcorresponding band of the optical filter shown in FIG. 8 . FIG. 9B showsa percentage difference in chroma between the output of the opticalfilter of FIG. 8 and the output of a filter that uniformly attenuatesthe same average percentage of light within each stimulus band as theoptical filter of FIG. 8 , wherein the input is a 30 nm uniformintensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band.

Many other variations in the location and number of absorptance peaksare possible. For example, some embodiments significantly attenuatelight between about 558 nm and about 580 nm by providing a peak at about574 nm and adding an additional peak at about 561 nm. Such embodimentscan provide substantially greater chroma in the green region, which iscentered near about 555 nm.

In certain embodiments, an optical filter increases chroma in thevisible spectrum by increasing the degree to which light within thebandwidth of each absorptance peak is attenuated. The degree of lightattenuation within the spectral bandwidth of an absorptance peak can becharacterized by an “attenuation factor” defined as the integratedabsorptance peak area within the spectral bandwidth of the absorptancepeak divided by the spectral bandwidth of the absorptance peak. Anexample of an absorptance peak with an attenuation factor of 1 is asquare wave. Such an absorptance peak attenuates substantially all lightwithin its spectral bandwidth and substantially no light outside itsspectral bandwidth. In contrast, an absorptance peak with an attenuationfactor of less than 0.5 attenuates less than half of the light withinits spectral bandwidth and may attenuate a significant amount of lightoutside its spectral bandwidth. It may not be possible to make anoptical filter having an absorptance peak with an attenuation factor ofexactly 1, although it is possible to design an optical filter having anabsorptance peak with an attenuation factor that is close to 1.

In certain embodiments, an optical filter is configured to have one ormore absorptance peaks with an attenuation factor close to 1. Many otherconfigurations are possible. In some embodiments, an optical filter hasone or more absorptance peaks with an attenuation factor greater than orequal to about 0.8, greater than or equal to about 0.9, greater than orequal to about 0.95, greater than or equal to about 0.98, between about0.8 and about 0.99, greater than or equal to about 0.8 and less than 1,or between any of the other foregoing values. Collectively, theforegoing limitations on attenuation factor can be called “attenuationfactor criteria.” In certain embodiments, the attenuation factor of eachabsorptance peak in an optical filter meets one or more of theattenuation factor criteria. In some embodiments, the attenuation factorof each absorptance peak having a maximum absorptance over a certainabsorptance threshold in an optical filter meets one or more of theattenuation factor criteria. The absorptance threshold can be about 0.5,about 0.7, about 0.9, about 1, between 0.5 and 1, or another value. Itis understood that while certain spectral features are described hereinwith reference to an optical filter, each of the spectral features canequally apply to the spectral profile of a lens containing the opticalfilter, unless indicated otherwise.

In some embodiments, an optical filter has absorptance peaks in each offour spectral bands, each of which has an attenuation factor greaterthan or equal to about 0.95. Because it is rare to observe monochromaticlight in the physical world, some narrow bands of light can be nearly orcompletely blocked out without significant detriment to the overallvariety of perceived spectral colors in the natural world. In otherwords, the optical filter can be employed in everyday vision without theloss of any substantial visual information. A spectral absorptanceprofile of an example optical filter having these attributes is shown inFIG. 11 . Relative chroma profiles and a chromaticity diagram for thesame optical filter are shown in FIGS. 12A, 12B, and 13 . The relativechroma profiles shown in FIG. 12A include the chroma profile of aneutral filter having the same integrated light transmittance withineach 30 nm stimulus band as within each corresponding band of theoptical filter shown in FIG. 8 , indicated by a thicker black line, andthe chroma profile of the wavelength-dependent filter shown in FIG. 8 ,which is indicated by a thinner black line and is generally higher thanthe neutral filter profile. FIG. 12B shows a percentage difference inchroma between the output of the optical filter of FIG. 11 and theoutput of a filter that uniformly attenuates the same average percentageof light within each stimulus band as the optical filter of FIG. 11 ,wherein the input is a 30 nm uniform intensity stimulus and thehorizontal axis indicates the center wavelength of each stimulus band.

In some embodiments, an optical filter has one or more absorptance peakswith a bandwidth that is at least partially within a chroma enhancementwindow. The width of the chroma enhancement window can be between about22 nm and about 45 nm, between about 20 nm and about 50 nm, greater thanor equal to about 20 nm, greater than or equal to about 15 nm, oranother suitable bandwidth range. In certain embodiments, an opticalfilter is configured such that every absorptance peak with anattenuation factor greater than or equal to an absorptance threshold hasa bandwidth within a chroma enhancement window. For example, thebandwidth of each of the absorptance peaks can be greater than or equalto about 10 nm, greater than or equal to about 15 nm, greater than orequal to about 20 nm, greater than or equal to about 22 nm, less than orequal to about 60 nm, less than or equal to about 50 nm, less than orequal to about 40 nm, between about 10 nm and about 60 nm, between about20 nm and about 45 nm, or between any of the other foregoing values.

Variations in the bandwidth (e.g., the FWHM value) and in the slopes ofthe sides of an absorptance peak can have marked effects on chroma.Generally, increases in the FWHM and/or slopes of the chroma-enhancingpeaks are accompanied by increases in chroma and vice-versa, in the caseof chroma-lowering peaks. In FIGS. 14 and 16 , example optical filtersare shown where the FWHM and slopes of an absorptance peak areseparately varied. The effects of these variations on chroma are shownin the accompanying chroma profiles in FIGS. 15A-15B and 17A-17B. InFIG. 14 , an overlay of absorptance peaks centered at 478 nm for threedifferent filters F1, F2, and F3 is shown. The absorptance peaks haveequal side slopes and varying FWHM values, with filter F1 having thelowest FWHM value and filter F3 having the highest FWHM value. Therelative chroma profile in FIG. 15A shows the effect of the filters F1,F2, and F3 shown in FIG. 14 on chroma. The absorptance and chromaprofiles of each of the filters F1, F2, and F3 are shown with the samecorresponding line style in each graph, with a neutral filter includedas a thick line in FIG. 15A. FIG. 15B shows a percentage difference inchroma between the output of the three optical filters F1, F2, and F3 ofFIG. 14 and the output of a filter that uniformly attenuates the sameaverage percentage of light within each stimulus band as the opticalfilters of FIG. 14 , wherein the input in each case is the same 30 nmuniform intensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band.

FIG. 16 shows an overlay of three absorptance peaks centered at 478 nm,with equal FWHM and varying slopes. FIG. 17A shows the effect of thefilters F4, F5, and F6 shown in FIG. 16 on chroma, with a neutral filteragain included as a thick solid line. FIG. 17B shows a percentagedifference in chroma between the output of the three optical filters F4,F5, and F6 of FIG. 16 and the output of a filter that uniformlyattenuates the same average percentage of light within each stimulusband as the optical filters of FIG. 16 , wherein the input in each caseis the same 30 nm uniform intensity stimulus and the horizontal axisindicates the center wavelength of each stimulus band.

Returning to the optical filter shown in FIG. 11 , the outer twoabsorptance peaks centered at 415 nm and 715 nm have outside slopes(i.e., at the lower limit of the 415 nm peak and at the upper limit ofthe 715 nm peak) that affect light wavelengths at generally the fringesof the visible spectrum. In some embodiments, the absorptance profilesof these peaks can be altered to significantly, mostly, or almostentirely attenuate light at wavelengths outside of about the 400 nm to700 nm range, which can be regarded as the dominant portion of thevisible range. The spectral absorptance profile of an example opticalfilter having these attributes is shown in FIG. 18 . Relative chromaprofiles and the chromaticity diagram for the same optical filter areshown in FIGS. 19A, 19B, and 20 . FIG. 19B shows a percentage differencein chroma between the output of the optical filter of FIG. 18 and theoutput of a filter that uniformly attenuates the same average percentageof light within each stimulus band as the optical filter of FIG. 18 ,wherein the input is a 30 nm uniform intensity stimulus and thehorizontal axis indicates the center wavelength of each stimulus band.

By controlling chroma according to the techniques disclosed herein, thechroma of one or more color bands can also be decreased in situationswhere less colorfulness in those color bands is desired. In someembodiments, an optical filter can be configured to decrease chroma inone or more color bands and increase chroma in other color bands. Forexample, eyewear designed for use while hunting ducks can include one ormore lenses with an optical filter configured to lower the chroma of ablue background and increase the chroma for green and brown feathers ofa duck in flight. More generally, an optical filter can be designed tobe activity-specific by providing relatively lower chroma in one or morespectral regions associated with a specific background (e.g., theground, the sky, an athletic field or court, a combination, etc.) andproviding relatively high chroma in one or more spectral regionsassociated with a specific foreground or object (e.g., a ball).Alternatively, an optical filter can have an activity-specificconfiguration by providing increased chroma in both a backgroundspectral region and an object spectral region.

The ability to identify and discern moving objects is generally called“Dynamic Visual Acuity.” An increase in chroma in the spectral region ofthe moving object is expected to improve this quality because increasesin chroma are generally associated with higher color contrast.Furthermore, the emphasis and de-emphasis of specific colors can furtherimprove Dynamic Visual Acuity. A spectral absorptance profile of anexample optical filter configured to increase Dynamic Visual Acuity isshown in FIG. 21 . The optical filter shown is configured to providehigh chroma in the green to orange spectral region and relatively lowerchroma in the blue spectral region. The relative chroma profiles and thechromaticity diagram of the same optical filter are shown in FIGS. 22A,22B, and 23 . FIG. 22B shows a percentage difference in chroma betweenthe output of the optical filter of FIG. 21 and the output of a filterthat uniformly attenuates the same average percentage of light withineach stimulus band as the optical filter of FIG. 21 , wherein the inputis a 30 nm uniform intensity stimulus and the horizontal axis indicatesthe center wavelength of each stimulus band.

In some embodiments, an optical filter is configured to account forvariation in luminous efficiency over the visible spectrum. Byaccounting for luminous efficiency, the filter can compensate fordifferences in relative sensitivities at different wavelengths of thehuman eye to various color bands can be compared. Luminous efficiencyover the visible spectrum, consistent with the Stockman and Sharpe conesensitivity data, is shown in FIG. 24 .

In certain embodiments, an optical filter is configured to selectivelyincrease chroma in the red wavelengths at which the human eye is mostsensitive. For example, the red color band can be described as thespectral range extending between about 625 nm and about 700 nm. Whenlooking at the luminous efficiency function shown in FIG. 24, it isapparent that the eye is significantly more sensitive to red lightbetween about 625 nm and 660 nm than at longer wavelengths. Accordingly,a spectral absorptance profile of an optical filter with thisconfiguration is shown in FIG. 25 . The optical filter has the sameprofile as the one shown in FIG. 11 except that it has an alternate peakin the red band centered at about 658 nm instead of a peak centered atabout 715 nm. The result is increased chroma over the red band up to 655nm with an accompanying decrease in chroma for red above 660 nm, wherethe eye is less sensitive. The relative chroma profiles and thechromaticity diagram for the same optical filter are shown in FIGS. 26A,26B, and 27 . FIG. 26B shows a percentage difference in chroma betweenthe output of the optical filter of FIG. 25 and the output of a filterthat uniformly attenuates the same average percentage of light withineach stimulus band as the optical filter of FIG. 25 , wherein the inputis a 30 nm uniform intensity stimulus and the values along horizontalaxis indicate the center wavelength of each stimulus band.

Additionally, chroma can be increased for wavelengths in the middle ofthe green range using an absorptance peak centered at about 553 nm, atabout 561 nm, or at a wavelength between about 550 nm and about 570 nm.Such a filter can also decrease chroma of yellow colors, so it may beused in activities that benefit from identifying green objects that areviewed against a yellow background. A spectral absorptance profile foran optical filter that provides increased chroma for the middle of thegreen spectral range is shown in FIG. 28 . The relative chroma profilesand the chromaticity diagram for the same optical filter are shown inFIGS. 29A, 29B, and 30 , respectively. FIG. 29B shows a percentagedifference in chroma between the output of the optical filter of FIG. 28and the output of a filter that uniformly attenuates the same averagepercentage of light within each stimulus band as the optical filter ofFIG. 28 , wherein the input is a 30 nm uniform intensity stimulus andthe horizontal axis indicates the center wavelength of each stimulusband.

In order to fabricate the filter profiles shown above, a variety ofapproaches can be applied, such as through the use of dielectric stacks,multilayer interference coatings, rare earth oxide additives, organicdyes, or a combination of multiple polarization filters as described inU.S. Pat. No. 5,054,902, the entire contents of which are incorporatedby reference herein and made a part of this specification. Anothersuitable fabrication technique or a combination of techniques can alsobe used.

In certain embodiments, an optical filter includes one or more organicdyes that provide absorptance peaks with a relatively high attenuationfactor. For example, in some embodiments, a lens has an optical filterincorporating organic dyes supplied by Exciton of Dayton, Ohio. At leastsome organic dyes supplied by Exciton are named according to theapproximate center wavelength of their absorptance peak. An approximatedspectral absorptance profile of a non-polarized polycarbonate lens withan optical filter incorporating Exciton ABS 407, ABS 473, ABS 574, andABS 659 dyes is shown in FIG. 31 . The organic dye formulation of theoptical filter provides absorptance peaks at about 407 nm, 473 nm, 574nm, and 659 nm. The relative chroma profiles and the chromaticitydiagram of the lens are shown in FIGS. 32A, 32B, and 33 , respectively.FIG. 32B shows a percentage difference in chroma between the output ofthe optical filter of FIG. 31 and the output of a filter that uniformlyattenuates the same average percentage of light within each stimulusband as the optical filter of FIG. 31 , wherein the input is a 30 nmuniform intensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band.

Some embodiments are similar to the embodiments described in theprevious paragraph, but include a red absorptance peak positioned at 647nm using Exciton ABS 647 dye instead of Exciton ABS 659 dye. In suchembodiments, the chroma for the higher luminous efficiency red hueslocated closer to the peak of the human eye's sensitivity is increased.The spectral absorptance profile of a non-polarized polycarbonate lenswith an optical filter in this configuration is shown in FIG. 34 . Theprofile includes absorptance peaks at 407 nm, 473 nm, 574 nm, and 647nm. The relative chroma profiles and the chromaticity diagram of thelens are shown in FIGS. 35A, 35B, and 36 , respectively. FIG. 35B showsa percentage difference in chroma between the output of the opticalfilter of FIG. 34 and the output of a filter that uniformly attenuatesthe same average percentage of light within each stimulus band as theoptical filter of FIG. 34 , wherein the input is a 30 nm uniformintensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band.

In some embodiments, another optical filter is configured to increase ormaximize chroma across several, many, or most colors, or at least manycolors that are commonly encountered in the environment of the wearer.Such an optical filter can include a plurality of absorptance peaks. Theplurality of absorptance peaks can include an absorptance peak having acenter wavelength between about 415 nm and about 455 nm, at about 478nm, and between about 555 nm and 580 nm, and at about 660 nm. The FWHMvalues of the plurality of absorptance peaks can be between about 20 nmand about 50 nm, greater than about 20 nm, about 22 nm, about 45 nm,another suitable value, or a combination of values. In some embodiments,the FWHM value of the absorptance peak with a center wavelength betweenabout 555 nm and about 580 nm is about twice the FWHM value of at leastsome of the other absorptance peaks in the spectral profile. Anapproximated spectral absorptance profile of an example filter havingabsorptance peaks reflected by the embodiments described in thisparagraph is shown in FIG. 37 . The example filter has a sharp drop inabsorptance at about 490 nm that permits substantial transmission oflight at 491 nm and through a wide band (for example, through a spectralband greater than or equal to about 20 nm in bandwidth) in theneighborhood of 491 nm (for example, through a band of wavelengths near491 nm and greater than or equal to about 491 nm).

A relative chroma profile for a filter having the absorptance profile ofFIG. 37 is shown in FIG. 38A. The chroma profile of FIG. 38A is shownwith a vertical scale different from other chroma profiles in thisdisclosure in order to show larger variation in chroma. The examplefilter produces substantial increases in relative chroma over theunfiltered case in multiple spectral bands, including in spectral bandsbetween about 410 nm and about 460 nm, between about 465 nm and about475 nm, between about 480 nm and about 500 nm, between about 540 nm andabout 565 nm, between about 570 nm and 600 nm, and between about 630 nmand about 660 nm. FIG. 38B shows a percentage difference in chromabetween the output of the optical filter of FIG. 37 and the output of afilter that uniformly attenuates the same average percentage of lightwithin each stimulus band as the optical filter of FIG. 37 , wherein theinput is a 30 nm uniform intensity stimulus and the horizontal axisindicates the center wavelength of each stimulus band. A chromaticitydiagram for this example filter is shown in FIG. 39 .

In some embodiments, two or more dyes can be used to create a singleabsorptance peak or a plurality of absorptance peaks in close proximityto one another. For example, an absorptance peak with a centerwavelength positioned between about 555 nm and about 580 nm can becreating using two dyes having center wavelengths at about 561 nm and574 nm. In another embodiment, an absorptance peak with a centerwavelength positioned between about 555 nm and about 580 nm can becreating using two dyes having center wavelengths at about 556 nm and574 nm. While each dye may individually produce an absorptance peakhaving a FWHM value of less than about 30 nm, when the dyes are usedtogether in an optical filter, the absorptance peaks may combine to forma single absorptance peak with a FWHM value of about 45 nm or greaterthan about 40 nm.

Filters incorporating organic dyes can be fabricated using any suitabletechnique. In some embodiments, a sufficient quantity of one or moreorganic dyes is used to lower transmittance in one or more spectralregions to less than or equal to about 1%. To achieve peaktransmittances under 1% in 1.75 mm thick polycarbonate lenses, dyes canbe mixed into a batch of polycarbonate resin. If the mixture includes 5lbs of polycarbonate resin, the following loadings of Exciton dyes canbe used for the optical filter associated with the absorptance profileshown in FIG. 31 : 44 mg of ABS 407, 122 mg of ABS 473, 117 mg of ABS574, and 63 mg of ABS 659. In the foregoing example, the ratios of dyeloadings in polycarbonate can be generalized as follows: out of 1000total units of dye, the filter could include about 130 units ofviolet-absorbing dye, about 350 units of blue-absorbing dye, about 340units of green-absorbing dye, and about 180 units of deep red-absorbingdye.

In the same quantity of polycarbonate resin, the following loadings ofExciton dyes can be used for the optical filter associated with theabsorptance profile shown in FIG. 34 : 44 mg of ABS 407, 122 mg of ABS473, 117 mg of ABS 574, and 41 mg of ABS 647. In the foregoing example,the ratios of dye loadings in polycarbonate can be generalized asfollows: out of 995 total units of dye, the filter could include about135 units of violet-absorbing dye, about 375 units of blue-absorbingdye, about 360 units of green-absorbing dye, and about 125 units ofred-absorbing dye. In certain embodiments, a lens can be created fromthe resin and dye mixture by a casting process, a molding process, orany other suitable process.

Other dyes for plastic exist that can also provide substantial increasesin chroma. For example, Crysta-Lyn Chemical Company of Binghamton, NYoffers DLS 402A dye, with an absorptance peak at 402 nm. In someembodiments, the DLS 402A dye can be used in place of the Exciton ABS407 dye in the formulations described above. Crysta-Lyn also offers DLS461B dye that provides an absorptance peak at 461 nm. DLS 461B dye canbe used in place of the Exciton ABS 473 dye in the formulationsdescribed above. Crysta-Lyn DLS 564B dye can be used in place of theExciton ABS 574 dye in those formulations, while Crysta-Lyn DLS 654B dyecan be used in place of Exciton ABS 659 dye. In some embodiments, thedye can be incorporated into one or more lens components, and thedecision regarding which lens components include the dye can be based onproperties, such as stability or performance factors, of each specificdye.

In another example, an optical filter is designed with relative amountsof certain dyes. The magnitude of absorptance peaks can be selected byadjusting the absolute mass loading of the dyes while maintaining therelative relationships between loadings of different dyes. For example,in a particular embodiment, an organic dye optical filter includes: 70mg of Exciton ABS 473 dye, 108 mg of Exciton ABS 561 dye, 27 mg ofExciton ABS 574 dye, and 41 mg of Exciton ABS 659. The ratios of dyeloadings in polyurethane can be generalized as follows: out of 1000total units of dye, the filter could include about 280 units ofblue-absorbing dye, about 440 units of yellow-green-absorbing dye, about110 units of green-absorbing dye, and about 170 units of deepred-absorbing dye. A lens was cast using the foregoing dye loadings in251 g of polyurethane. The resulting lens had a thickness of 1.9 mm.Loading levels can be adjusted to account for the characteristics of theparticular base material used. For example, the loading levels may besomewhat or slightly higher when using a material with a lower density,such as certain types of polycarbonate. Likewise, the loading levels canbe somewhat or slightly lower when a higher density material is used.

The absorptance profile of the cast lens is shown in FIG. 40 . In theabsorptance profile shown in FIG. 40 , the absorptance peak centered atabout 477 nm has a full width at 80% of the maximum absorptance of theabsorptance peak of about 46 nm and an attenuation factor of about 0.92.The absorptance peak centered at about 569 nm has a full width at 80% ofthe maximum absorptance of the absorptance peak of about 35 nm and anattenuation factor of about 0.86. The absorptance peak centered at about660 nm has a full width at 80% of the maximum absorptance of theabsorptance peak of about 27 nm and an attenuation factor of about 0.91.The cast lens provided an increase in chroma in multiple spectralregions, as shown in FIGS. 41A and 41B. The chroma profile of FIG. 41Ais shown at a scale different from other chroma profiles in thisdisclosure. FIG. 41B shows a percentage difference in chroma between theoutput of the optical filter of FIG. 40 and the output of a filter thatuniformly attenuates the same average percentage of light within eachstimulus band as the optical filter of FIG. 40 , wherein the input is a30 nm uniform intensity stimulus and the horizontal axis indicates thecenter wavelength of each stimulus band. A chromaticity diagram for thecast lens is shown in FIG. 42 .

FIG. 50 illustrates the absorptance profile as a function of wavelengthof an optical filter of FIG. 40 combined with a light-grey polarizerfilm where the luminous transmittance using CIE standard illuminant D65is about 9.3%. The luminous transmittance of a polarizing sunglass lensincorporating a chroma enhancement filter as disclosed herein can beless than or equal to about 15%, less than or equal to about 12%, lessthan or equal to about 10%, less than or equal to about 9%, greater thanor equal to about 7%, greater than or equal to about 8%, between about7%-15%, between about 7%-12%, between about 9%- 12%, or another suitablevalue. Moreover, a lens may exhibit a heterogeneous transmittanceprofile having a combination of two or more transmittance regions havingdifferent transmittances. FIG. 51 shows a percentage difference inchroma between the output of a lens having the absorptance profile ofFIG. 50 and the output of a filter that uniformly attenuates the sameaverage percentage of light within each stimulus band as the lens withthe absorptance profile of FIG. 50 , wherein the input is a 30 nmuniform intensity stimulus and the horizontal axis indicates the centerwavelength of each stimulus band. A chromaticity diagram for a lens withthe absorptance profile of FIG. 50 is shown in FIG. 52 .

In some embodiments, one or more of the dyes used in any filtercomposition disclosed herein can be replaced by one or more dyes havingsimilar spectral attributes. For example, if a dye, such as the ExcitonABS 473 dye, is not sufficiently stable to endure the lens formationprocess, one or more substitute dyes with improved stability and asimilar absorptance profile can be used, instead. Some lens formationprocesses, such as injection molding, can subject the lens and opticalfilter to high temperatures, high pressures, and/or chemically activematerials. Replacement dyes can be selected to have similar absorptanceprofiles of the dyes disclosed herein but improved stability orperformance. For example, a replacement dye can exhibit high stabilityduring injection molding of the lens or high stability under sunlight.In one embodiment, at least one of two or more dyes can be used in placeof Exciton ABS 473 dye. In one embodiment, Exciton ABS 473 dye wasreplaced with a dye that has an absorptance peak with a centerwavelength of about 477 nm in polycarbonate. In some embodiments, theattenuation factor associated with the 477 nm absorptance peak isgreater than or equal to about 0.8, greater than or equal to about 0.9,about 0.93, or another suitable value.

In some embodiments, a lens can include dyes or other materials that areselected or configured to increase the photostability of the chromaenhancing filter and other lens components. Any technique known in theart can be used to mitigate degradation of filter materials and/or otherlens components.

The relative quantities of any dye formulations disclosed herein can beadjusted to achieve a desired objective, such as, for example, a desiredoverall lens color, a chroma-enhancing filter having particularproperties, another objective, or a combination of objectives. Anoptical filter can be configured to have an absorptance profile with anycombination of the absorptance peaks disclosed herein and/or anycombination of other absorptance peaks in order to achieve desiredchroma-enhancing properties.

As described above, FIG. 41 illustrates a chroma profile of a cast lenswith an optical filter compared to the chroma profile of a neutralfilter with the same average attenuation within each 30 nm stimulusband. The chroma profile of the cast lens is represented by the lighterline and is generally higher than the chroma profile of the neutralfilter, which is represented by the thicker line. The cast lens isconfigured to provide multiple spectral regions of increased chromacompared to the neutral filter. In some embodiments, a lens includes anoptical filter containing one or more organic dyes. The one or moreorganic dyes can increase or decrease chroma in one or more spectralregions. As shown in FIG. 41 , an optical filter can be configured toincrease chroma in five or more spectral ranges. The spectral rangesover which an optical filter increases or decreases chroma can be calledchroma enhancement windows (CEWs).

In some embodiments, CEWs include portions of the visible spectrum inwhich an optical filter provides a substantial change in chroma comparedto a neutral filter having the same average attenuation within each 30nm stimulus band, as perceived by a person with normal vision. Incertain cases, a substantial enhancement of chroma can be seen when afilter provides a chroma increase greater than or equal to about 2%compared to the neutral filter. In other cases, a chroma increasegreater than or equal to about 3% or greater than or equal to about 5%compared to the neutral filter is considered a substantial increase.Whether a chroma change represents a substantial increase can depend onthe spectral region in which the increase is provided. For example, asubstantial chroma enhancement can include an increase in chroma greaterthan or equal to about 6% over a neutral filter when the visual stimulusis centered at about 560 nm. A substantial chroma enhancement caninclude an increase in chroma greater than or equal to about 3% over aneutral filter when the visual stimulus is centered at about 660 nm. Asubstantial chroma enhancement can include an increase in chroma greaterthan or equal to about 15% over a neutral filter when the visualstimulus is centered at about 570 nm. Accordingly, the amount of changein chroma relative to the neutral filter that is considered substantialmay differ depending on the spectral range of the CEW.

In certain embodiments, a substantial chroma enhancement is provided byan optical filter configured to increase chroma in one or more CEWs overa neutral filter without any significant decrease in chroma compared toa neutral filter within the one or more CEWs. A substantial chromaenhancement can also be provided by an optical filter configured toincrease chroma in one or more CEWs over a neutral filter without anysignificant decrease in chroma compared to a neutral filter within aparticular spectral range, such as, for example, between about 420 nmand about 650 nm.

FIGS. 43 through 48 illustrate various CEW configurations for a varietyof chroma-enhancing optical filters. The spectral ranges of the CEWs cancorrespond to the spectral regions where an optical filter exhibitssubstantially changed chroma compared to a neutral filter in one or moreof FIGS. 6, 9, 12, 15, 17, 19, 22, 26, 29, 32, 35, 38 , and 41. Theparticular CEW configurations disclosed here are non-limiting examplesthat illustrate the wide variety of lens or eyewear configurations thatexist.

One example of an optical filter CEW configuration is shown in FIG. 43 .In this example, CEW₁ encompasses a spectral range of about 440 nm toabout 510 nm. CEW₂ encompasses a spectral range of about 540 nm to about600 nm. CEW₃ encompasses a spectral range of about 630 nm to about 660nm. Each CEW may be defined as a spectral range within which a lens oreyewear is configured to provide chroma enhancement. Alternatively, thelower end of one or more CEWs can encompass a wavelength above which thelens or eyewear provides chroma enhancement. The upper end of one ormore CEWs can encompass a wavelength below which the lens or eyewearprovides chroma enhancement. In some embodiments, the average increasein chroma within CEW₁ compared to a neutral filter having the sameaverage attenuation within each 30 nm stimulus band is greater than orequal to about 20%. The average increase in chroma within CEW₂ comparedto the neutral filter can be greater than or equal to about 3%. Theaverage increase in chroma within CEW₃ compared to a neutral filter canbe greater than or equal to about 5%.

Another example of an optical filter CEW configuration is shown in FIG.44 .

CEW_(1A) encompasses a spectral range of about 440 nm to about 480 nm.CEW_(1B) encompasses a spectral range of about 490 nm to about 510 nm.The average increase in chroma compared to a neutral filter can begreater than or equal to about 15% for the CEW_(1A) region and greaterthan or equal to about 15% for the CEW_(1B) region.

A further example of an optical filter CEW configuration is shown inFIG. 45 , which is a configuration in which CEW₂A encompasses a spectralrange of about 540 nm to about 570 nm. FIG. 46 illustrates an additionalembodiment in which an optical filter provides a CEW configurationincluding CEW_(1A), CEW_(1B), CEW_(2A), and CEW₃. The average increasein chroma compared to a neutral filter can be greater than or equal toabout 4% for the CEW_(2A) spectral region, for example.

FIG. 47 illustrates an example of an optical filter CEW configurationwith an additional enhancement window, CEW_(2B). The CEW_(2B) windowencompasses a spectral range between about 580 nm and about 600 nm. Theaverage increase in chroma compared to a neutral filter can be greaterthan or equal to about 2% for the CEW_(2B) spectral region, for example.FIG. 48 illustrates the relative chroma enhancement of an optical filterconfigured to provide five or more chroma enhancement windows,including: CEW_(2A), CEW_(2B), CEW_(1A), CEW_(1B), and CEW₃. Each ofFIGS. 43 through 48 illustrates a non-limiting example of an opticalfilter CEW configuration, and this disclosure should not be interpretedas limited to any specific configuration or combination ofconfigurations.

In some embodiments, an optical filter is configured to enhance objectvisibility while preserving the natural appearance of viewed scenes.Such optical filters (and eyewear that include such filters) can beconfigured for a wide range of recreational, sporting, professional, andother activities. As a representative example, filters and eyewear canbe configured to be worn while playing a game of golf

In certain embodiments, eyewear and optical filters provide one or moreCEWs corresponding to a specific activity. A filter can include one ormore CEWs in a portion of the visible spectrum in which an object ofinterest, such as, for example, a golf ball, emits or reflects asubstantial spectral stimulus. When referring to the spectral stimulusof an object of interest, a corresponding CEW may be referred to as theobject spectral window. When referring to spectral stimulus of abackground behind an object, a corresponding CEW may be referred to asthe background spectral window. Moreover, when referring to the spectralstimulus of the general surroundings, the spectral window may bereferred to as the surrounding spectral window. An optical filter can beconfigured such that one or more edges of an absorptance peak lie withinat least one spectral window. In this way, an optical filter can enhancechroma in the spectral ranges corresponding to a given spectral stimulus(e.g. object, background, or surroundings).

Golf balls and corresponding eyewear can be provided in which a golfball cover is configured to produce wavelength-converted light, and theeyewear includes lenses having an object chroma enhancement windowcorresponding to a spectral reflectance of the cover, a spectraltransmittance of any transparent or translucent outer portion of thecover, and/or a spectrum of wavelength-converted light emitted by thecover.

Golf balls are provided that have a cover that is configured towavelength-convert light that is incident at a first wavelength or in afirst wavelength range. The wavelength-converted light can be emitted atlonger wavelengths than the wavelength of the absorbed incident light.The wavelength-converted light has at least a portion corresponding toan object chroma enhancement window of corresponding eyewear. Inrepresentative examples, the golf balls have covers that include afluorescent material that produces fluorescence in a spectral regioncorresponding to a spectral transmittance of a viewing filter. Inadditional embodiments, a portion of the object chroma enhancementwindow corresponds to a spectral region in which light is preferentiallyreflected by the cover.

Methods of enhancing object visibility with respect to a backgroundinclude providing a filter that increases the chroma of the object to beviewed. A light spectrum produced by the filter can define an objectchroma enhancement window. An optical filter is provided that includes aspectral window corresponding to the object chroma enhancement window,and a background chroma enhancement window corresponding to a reflectedor emitted spectral profile of the background. An improved opticalfilter can provide for chroma enhancement within the spectral windows.In some embodiments, the contrast agent is a wavelength-conversionagent, a colorant, or both. In alternative examples, the optical filterincludes a spectral-width window that broadens the transmission spectrumof the filter. In some particular examples, the object chromaenhancement window, the background chroma enhancement window, and thespectral-width window include wavelengths from about 440 nm to about 480nm, about 510 nm to about 580 nm, and about 600 nm to about 660 nm,respectively. In additional examples, the windows include wavelengthsbetween about 400 nm and about 700 nm. Lenses can include spectralwindows that exhibit chroma enhancement within the same spectral rangesthat define the spectral windows. In such embodiments, the lens canprovide increased chroma or decreased chroma within one or more of thespectral windows discussed herein.

These and other features and aspects of certain embodiments aredescribed below with reference to golf and other sporting andnon-sporting applications. For convenience, several representativeexamples pertaining to golf are described, but it will be apparent thatthese examples can be modified in arrangement and detail for otherleisure, recreational, sporting, industrial, professional, or otheractivities.

Viewing a golf ball's trajectory and determining its location areimportant to golfers of various skill levels. Trajectories of a golfball hit by an inexperienced golfer are unpredictable and frequentlyplace the ball in locations in which the ball is hard to find. Suchfailures to promptly find a golf ball can increase the time used to playa round and can reduce the number of rounds that can be played on acourse in a day. Because time spent looking for errant golf ballscontributes to slow play, many courses and many tournaments have rulesconcerning how long a golfer is permitted to search for a lost golf ballbefore putting a replacement ball into play. For more experienced orexpert golfers, loss of a golf ball results in imposition of a penaltythat adds strokes to the golfer's score. Such penalty strokes areannoying, especially when the loss of a ball results from an inabilityto find the ball due to poor viewing conditions and a limited time inwhich to search.

With reference to FIG. 49 , a spectral power distribution 300 ofradiation from a golf ball in outdoor illumination such as directsunlight or other illumination conditions includes a blue-enhancedportion 302 located in a wavelength region near a wavelength B. Theblue-enhanced portion 302 can be produced by conversion of radiationwithin a range of wavelengths shorter than that of the portion 302 toradiation at wavelengths within the blue-enhanced portion 302. Suchwavelength-conversion can result from fluorescence, phosphorescence, orother processes. As used herein, any process in which radiation at ashorter wavelength is converted into radiation at a longer wavelength isreferred to as a wavelength-conversion process. As noted above, atypical example of such a process is fluorescence in which radiation ata first wavelength is absorbed to produce radiation at a longerwavelength. Because the human eye is less sensitive to radiation atwavelengths shorter than the wavelengths of the blue-enhanced portion302 than to radiation within the blue-enhanced portion 302, conversionof radiation from the shorter wavelengths into longer wavelengthradiation tends to make the golf ball appear whiter and brighter. Thespectral power distribution of FIG. 49 corresponds to a golf ball thatappears white and spectral power distributions for non-white golf ballscan have additional spectral features characteristic of the golf ball'scolor.

Spectral power at wavelengths shorter than the conventional cutoff ofhuman visual response at wavelengths of about 400 nm is not shown inFIG. 49 . Radiation at these shorter wavelengths produces limited humanvisual response. Conversion of these shorter wavelengths into longerwavelengths by fluorescence or other wavelength-conversion process canproduce radiation that makes an appreciable contribution to visualresponse. This conversion process can be enhanced by the selection of agolf ball cover that produces such wavelength-converted light or byincorporating suitable fluorescent, phosphorescent, or otherwavelength-conversion agents into the golf ball cover. A typicalwavelength-conversion agent produces a blue-enhanced region at awavelength λ_(B) that is typically in the range between about 440 nm toabout 480 nm, but wavelength-conversion agents for other wavelengthranges can be used. If the golf ball (or other object of interest) neednot appear white, colored wavelength-conversion agents can be used, suchas colored fluorescent agents. In this example, AB and more particularlythe wavelength range in which AB typically occurs (i.e. from about 440nm to about 480 nm) represent an object spectral window.

The spectral power distribution 300 illustrated in FIG. 49 isrepresentative of the optical radiation from a golf ball under outdoorillumination conditions. More accurate spectral power distributionvalues depend on the exact illumination conditions. Typical illuminationconditions include illumination from direct sunlight and overcast skiesas well as illumination produced in deep shadows. Under these differentillumination conditions, different spectral power distributions areproduced. For example, an overcast sky typically produces a spectralpower distribution having less total energy as well as relatively lessenergy at shorter (more blue) wavelengths. Nevertheless, the spectralpower distributions associated with these varying illuminationconditions have corresponding blue-enhanced portions produced bywavelength-conversion processes.

Visual perception of a golf ball that produces the spectral powerdistribution of

FIG. 49 is improved by enhancing the chroma of the blue portion 302 (thewavelength-converted portion) of the golf ball spectral powerdistribution. The blue-enhanced portion 302 has excess blue spectralpower relative to the ambient illumination. Providing a blue lightchroma enhancing filter therefore permits improved tracking and locationof the golf ball. While enhancing the chroma of the blue portion 302 ofthe spectral power distribution of FIG. 49 permits increased golf ballvisibility under many conditions, the extent of this increasedvisibility depends on the background in which the golf ball is viewed.For common backgrounds encountered in golf such as fairway or puttingsurface grasses, chroma enhancement of the blue portion 302 can increasegolf ball visibility. Wearing eyewear that includes lenses that increasethe chroma of the blue-enhanced portion 302 can permit the golfer tomore readily follow the trajectory of a golf ball and to locate the golfball after it has come to rest.

While such eyewear can increase golf ball visibility and permit easiertracking and location of a golf ball, altering the spectral powerdistribution of light passing to the golfer's eyes can produce scenesthat appear unnatural or even disturbing to the golfer. During play of atypical round, the golfer encounters many different backgroundsincluding blue skies, overcast skies, rock, sand, dirt, and vegetation,including putting surfaces, fairways, sand traps, and rough. Eyewearthat enhances the chroma of the blue portion can produce an unnatural ordisturbing appearance to all or some of these surroundings, and impairthe golfer's concentration or perception. Such unnatural appearances canoffset any performance advantage associated with increased golf ballvisibility.

More natural appearing viewing can be obtained with an embodiment of anoptical filter having a spectral absorptance profile as illustrated inFIG. 40 . Such an embodiment provides improved golf ball visibilitywhile maintaining a natural appearance of scenes viewed through such afilter. As used herein, a spectral region in which an object emits orreflects a substantial spectral stimulus is referred to as a spectralwindow. A width of a spectral window can be defined as the full width atabout 75%, 50%, 25%, 20%, 10%, or 5% of a maximum in the spectral powerdistribution. A golf ball can include a blue light stimulus at andaround λ_(B) and one or more additional spectral windows in the greenand red portions of the spectrum.

A filter can include a chroma-enhancing window (CEW) that is configuredto enhance the chroma within a portion, substantially all, or the entirespectral window of a visual stimulus. An optical filter can provide oneor more edges of an absorptance peak within the spectral windows where astimulus is located. For example, the spectral location of a blue lightCEW can be selected to correspond to a particular fluorescent agent sothat eyewear can be spectrally matched to a particular fluorescentagent. Thus, eyewear and golf balls can be spectrally matched to provideenhanced golf ball visibility. Light at wavelengths below about 440 nmcan be attenuated so that potentially harmful short wavelength radiationdoes not enter the eye. For example, some of this short wavelengthradiation can be converted by the fluorescent agent to radiation atwavelengths corresponding to a blue light CEW. The average visible lighttransmittance of a golf lens can be about 20%-30%. Filters for outdooruse typically have average transmittances between about 8%-80%, 10%-60%,or 10%-40%. Filters for indoor use (or use at illumination levels lowerthan normal daylight illumination) can have average transmittancesbetween about 20%-90%, 25%-80%, or 40%-60%.

Green grass and vegetation typically provide a reflected or emittedspectral stimulus with a light intensity maximum at a wavelength ofabout 550 nm. As mentioned above, wavelengths from about 500 nm to about600 nm may define a green or background spectral window. Without a greenlight CEW, light at wavelengths between 500 nm and 600 nm can have lowerchroma than desired, and vegetation can appear relatively muted, drab,or dark. As a result, the golfer's surroundings would appear unnaturaland the golfer's perception of vegetation would be impaired. Thisimpairment is especially serious with respect to putting because thegolfer generally tries to precisely determine various parameters of theputting surface, including height and thickness of the grass coveringthe putting surface, orientation of the blades of grass of the puttingsurface, and the surface topography. Because a golfer takes aboutone-half of her strokes at or near putting surfaces, any visualimpairments at putting surfaces are serious performance disadvantagesand are generally unacceptable. Misperception of vegetation is also asignificant disadvantage when playing out of a fairway or rough. A greenlight CEW, in combination with a blue light CEW, permits enhanced golfball visibility while permitting accurate assessment of backgroundsurfaces such as putting surfaces or other vegetation. An optical filtercan enhance the chroma of a desired object and background by exhibitingat least one edge of an absorptance peak within one or both of the greenlight CEW and the blue light CEW. The concurrence of at least one edgeof an absorptance peak within one or both of the green or blue spectralwindows further aids the human eye in distinguishing a golf ball fromits surroundings by enhancing the chroma of the ball, the chroma of thevegetation, or the chroma of both the ball and vegetation.

A red light CEW may extend over a wavelength range from about 610 nm toabout 720 nm, but the transmission of radiation at wavelengths beyondabout 700 nm provides only a small contribution to a viewed scenebecause of the low sensitivity of the human eye at these wavelengths. Ared light CEW can enhance the natural appearance of scenery viewed withan embodiment of an improved optical filter by enhancing the chroma ofat least some red light reflected by vegetation. For example, chromaenhancement can be seen in FIG. 40 , where at least one edge of the redabsorptance peak (e.g., the absorptance peak between about 630 nm andabout 660 nm) falls within the red light CEW. The more polychromaticlight produced by enhancing the chroma of red, green, and bluecomponents of light permits improved focus. In addition, convergence(pointing of the eyes to a common point) and focusing (accommodation)are interdependent, so that improved focusing permits improvedconvergence and improved depth perception. Providing CEWs in the greenand red portions of the visible spectrum can result in improved depthperception as well as improved focus. A filter having such CEWs canimprove perception of vegetation (especially putting surfaces) andprovide more natural looking scenery while retaining the enhanced golfball visibility associated with the blue light CEW. An optical filterthat provides at least one edge of an absorption peak within a CEW canenhance the quality of the light transmitted through the optical filterby increasing its chroma value.

Optical filters having CEWs covering one or more spectral ranges canprovide enhanced visibility. Optical filters having such a spectralprofile can be selected for a particular application based on ease offabrication or a desire for the optical filter to appear neutral. Forcosmetic reasons, it can be desirable to avoid eyewear that appearstinted to others.

Optical filters can be similarly configured for a variety of activitiesin which tracking and observation of an object against a background isfacilitated by wavelength-conversion. Such filters can include awavelength-conversion window, a background window, and a spectral-widthwindow. These CEWs are selected to enhance the chroma ofwavelength-converted light, light from activity-specific backgrounds,and light at additional wavelengths to further extend the total spectralwidth of chroma-enhanced light to improve focus, accommodation, orprovide more natural viewing. For application to a white golf ball asdescribed above, an optical filter is provided with a blue light CEWcorresponding to wavelength-conversion spectral components, a greenlight CEW to facilitate viewing of a background, and a red light CEW toimprove accommodation and the natural appearance of scenes. Such anoptical filter can have a substantially neutral color density. For otheractivities, particular CEWs can be chosen based on expected or measuredbackground colors and wavelengths produced by a wavelength-conversionprocess. For example, tennis is often played on a green playing surfacewith a yellow ball. Such a ball typically has a wavelength conversionregion that produces wavelength-converted light at wavelengths betweenabout 460 nm and 540 nm. An example filter for such an application has awavelength-conversion window at between about 460 nm to about 540 nm,and a background window centered at about 550 nm. Thewavelength-conversion window and the background window can have someoverlap. To provide more natural contrast and better focus, additionaltransmission windows can be provided in wavelength ranges of about 440nm to about 460 nm, from about 620 nm to about 700 nm, or in otherranges.

In alternative embodiments, an optical filter having an object-specificspectral window in addition to or instead of a wavelength-conversionwindow is provided. For example, for viewing of a golf ball that appearsred, the optical filter can include a red light CEW that enhances thechroma of red light to improve golf ball visibility. For natural,accurate viewing of backgrounds (such as putting surfaces), a greenlight CEW is also provided. If the golf ball also emits wavelengthconverted light, an additional wavelength-conversion window can beprovided, if desired. The filter can also include a spectral-widthwindow.

In some embodiments, an optical filter is configured to change thechroma values of a scene in one or more spectral regions in which anobject and/or a background reflect or emit light. An optical filter canbe configured to account for spectral regions where an object ofinterest and the background reflect or emit light. Absorptance peaks canbe positioned such that chroma is increased or decreased in one or morespectral regions where the object of interest is reflecting or emittinglight and where the background is reflecting or emitting light. Forexample, chroma enhancement within an object or a background spectralwindow can be obtained by configuring an optical filter such that atleast one edge of an absorptance peak is positioned within the spectralwindow.

An optical filter can increase contrast between the object and thebackground by providing chroma enhancement in one or both of the objectspectral window and the background spectral window. Color contrastimproves when chroma is increased. For example, when a white golf ballis viewed against a background of green grass or foliage at a distance,chroma enhancement technology can cause the green visual stimulus to bemore narrowband. A narrowed spectral stimulus causes the greenbackground to appear less washed out, resulting in greater colorcontrast between the golf ball and the background.

With reference to FIGS. 1A and 1B, eyewear can include a frame andlenses 102 a and 102 b. The lenses 102 a and 102 b have a filter thatenhances chroma in a wavelength-conversion window, a background-window,a spectral-width window, another CEW, or any combination of CEWs. Forsome applications, the spectral-width window may be omitted. For otherapplications, an object-specific spectral window is provided that caninclude the wavelength-conversion window. The lenses 102 a and 102 b canbe corrective lenses or non-corrective lenses and can be made of any ofa variety of optical materials including glasses or plastics such asacrylics or polycarbonates. The lenses can have various shapes,including plano-plano and meniscus shapes. In alternative eyewear, aframe is configured to retain a unitary lens that is placed in front ofboth eyes when the eyewear is worn. Goggles can also be provided thatinclude a unitary lens that is placed in front of both eyes when thegoggles are worn.

The spectral transmittance profile and chroma enhancement of the lensesof FIGS. 1A and 1B can be obtained in several ways. A coating can beprovided to one or more surfaces of the lenses. Such coatings typicallyinclude one or more layers of coating materials configured to achieve adesired spectral transmittance and chroma enhancement. The layers can beabsorptive so that radiation from spectral regions that are to beattenuated is absorbed in the coating, or the coating can be reflectiveso that radiation at such wavelengths is reflected. In yet anotherexample, one or more dyes or other chromophores can be incorporatedwithin the lens material by a dyeing process or another process. Two ormore of the above methods can be combined to produce the desiredspectral and chroma characteristics.

While embodiments are described above with reference to particularactivities, additional examples can be provided for other activities.For example, a chroma-enhancing, enhanced-visibility filter can beprovided for sports such as baseball, tennis, badminton, basketball,racquetball, handball, archery, target shooting, trap shooting, cricket,lacrosse, football, ice hockey, field hockey, hunting, soccer, squash,or volleyball. For such sports, such a filter can include an objectchroma enhancement window selected to increase the chroma of naturalreflected light or wavelength-converted light produced by a fluorescentagent in a baseball, tennis ball, badminton birdie, or volleyball orlight that is preferentially reflected by these objects. Backgroundwindows and spectral-width windows can be provided so that backgroundsare apparent, scenes appear natural, and the wearer's focus and depthperception are improved. For sports played on various surfaces, or indifferent settings such as tennis or volleyball, different backgroundwindows can be provided for play on different surfaces. For example,tennis is commonly played on grass courts or clay courts, and filterscan be configured for each surface, if desired. As another example, icehockey can be played on an ice surface that is provided with awavelength-conversion agent or colorant, and lenses can be configuredfor viewing a hockey puck with respect to such ice. Outdoor volleyballbenefits from accurate viewing of a volleyball against a blue sky, andthe background filter can be selected to permit accurate backgroundviewing while enhancing chroma in outdoor lighting. A differentconfiguration can be provided for indoor volleyball. Eyewear thatincludes such filters can be activity-specific, surface-specific, orsetting-specific. In addition, tinted eyewear can be provided foractivities other than sports in which it is desirable to identify,locate, or track an object against backgrounds associated with theactivity. Some representative activities include dentistry, surgery,bird watching, fishing, or search and rescue operations. Such filterscan also be provided in additional configurations such as filters forstill and video cameras, or as viewing screens that are placed for theuse of spectators or other observers. Filters can be provided as lenses,unitary lenses, or as face shields. For example, a filter for hockey canbe included in a face shield.

It is contemplated that the particular features, structures, orcharacteristics of any embodiments discussed herein may be combined inany suitable manner in one or more separate embodiments not expresslyillustrated or described. For example, it is understood that an opticalfilter can include any suitable combination of light attenuationfeatures and that a combination of light-attenuating lens elements cancombine to control the chroma of an image viewed through a lens. In manycases, structures that are described or illustrated as unitary orcontiguous can be separated while still performing the function(s) ofthe unitary structure. In many instances, structures that are describedor illustrated as separate can be joined or combined while stillperforming the function(s) of the separated structures. It is furtherunderstood that the optical filters disclosed herein may be used in atleast some lens configurations and/or optical systems besides lenses.

It should be appreciated that in the above description of embodiments,various features are sometimes grouped together in a single embodiment,figure, or description thereof for the purpose of streamlining thedisclosure and aiding in the understanding of one or more of the variousinventive aspects. This method of disclosure, however, is not to beinterpreted as reflecting an intention that any claim require morefeatures than are expressly recited in that claim. Moreover, anycomponents, features, or steps illustrated and/or described in aparticular embodiment herein can be applied to or used with any otherembodiment(s). Thus, it is intended that the scope of the inventionsherein disclosed should not be limited by the particular embodimentsdescribed above, but should be determined only by a fair reading of theclaims that follow.

1-20. (canceled)
 21. A lens for an eyewear, comprising: an opticalfilter configured to attenuate visible light in a plurality of spectralbands, each of the plurality of spectral bands comprising an absorptancepeak having a maximum absorptance and a spectral bandwidth equal to thefull width of the absorptance peak at 80% of the maximum absorptance ofthe absorptance peak, and to provide high chroma in a green to orangespectral regions and lower chroma in a blue spectral region, the chromavalue being the C* attribute of the CIE L*C*h* color space, wherein theoptical filter comprises a blue light absorptance peak, wherein: themaximum absorptance of the blue light absorptance peak is between about440 nm and about 510 nm; and the spectral bandwidth associated with theblue light absorptance peak is less than or equal to 50 nm.
 22. The lensof claim 21, wherein the optical filter further comprises: a yellowlight absorptance peak, wherein the maximum absorptance of the yellowlight absorptance peak is between about 540 nm and about 600 nm.
 23. Thelens of claim 21, wherein the optical filter has an average visiblelight transmittance from about 8% to about 80%.
 24. The lens of claim21, wherein the optical filter has a CIE chromaticity x value betweenabout 0.3 and about 0.34.
 25. The lens of claim 21, wherein the opticalfilter further comprises a lens body and a functional layer disposedover the lens body.
 26. The lens of claim 21, wherein the green toorange spectral regions are from about 525 nm to about 600 nm.
 27. Aneyewear comprising the lens of claim
 21. 28. A lens for an eyewear,comprising: an optical filter configured to attenuate visible light inat least a first spectral band, a second spectral band, and a thirdspectral band, wherein: the first spectral band comprises a firstabsorptance peak; a maximum absorptance associated with the firstabsorptance peak is in the wavelength range of about 450 nm to about 530nm; the second spectral band comprises a second absorptance peak; themaximum absorptance associated with the second absorptance peak is inthe wavelength range of about 540 nm to about 600 nm; the third spectralband comprises a third absorptance peak; and the maximum absorptanceassociated with the third absorptance peak is in the wavelength range ofabout 640 nm to about 690 nm.
 29. The lens of claim 28, wherein thesecond spectral band comprises a fourth absorptance peak.
 30. The lensof claim 29, wherein the maximum absorptance associated with the secondabsorptance peak and the fourth absorptance peak is from about 80% toabout 100%.
 31. The lens of claim 28, wherein the optical filter has aCIE chromaticity x value between about 0.3 and about 0.38.
 32. The lensof claim 28, wherein the optical filter has a CIE chromaticity y valuebetween about 0.31 to about 0.39.
 33. The lens of claim 28, wherein theoptical filter has an average visible light transmittance from about 8%to about 80%.
 34. The lens of claim 28, wherein the lens has a luminoustransmittance from about 7% to about 15%.
 35. The lens of claim 28,wherein a maximum absorptance of the first absorptance peak is fromabout 80% to about 100%.
 36. An eyewear comprising the lens of claim 28.37. A lens for an eyewear, comprising: an optical filter configured toprovide a spectral absorptance profile to increase the average chromavalue of uniform intensity light stimuli having a bandwidth of 30 nmtransmitted through the optical filter at least partially within a firstfiltered portion of a visible spectrum by attenuating a portion of thelight transmitted by the optical filter in the first filtered portion ofthe visible spectrum, the chroma value being the C* attribute of the CIEL*C*h* color space, and to decrease the average chroma value within asecond filtered portion of the visible spectrum; wherein the firstfiltered portion comprises a spectral range of about 625 nm to about 655nm; wherein the second filtered portion comprises a spectral range fromabout 660 nm to about 700 nm; and wherein the lens has an averagevisible light transmittance between about 8% to about 80%.
 38. The lensof claim 37, wherein the increase in average chroma value compared tothe neutral filter is from about 0.5% to about 15% within the firstfiltered portion.
 39. The lens of claim 38, wherein the increase inaverage chroma value compared to the neutral filter is from about 3% toabout 15% within the first filtered portion.
 40. The lens of claim 37,wherein a maximum absorptance of the spectral absorptance profile isfrom about 50% to about 80% within the second filtered portion.
 41. Aneyewear comprising the lens of claim 37.